Organometallic and Coordination compounds of Transition Elements

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					                                                Research Group n. 4
                                     UNIVERSITA’ DEGLI STUDI DI PISA


         Organometallic and Coordination compounds of Transition Elements:
                      Preparation, Reactivity and Applications
 Fabio Marchetti,a Fabio Marchetti,b Guido Pampaloni, Filippo Renili
 a
     , Born in Bologna in 1974, b Born in Castelfiorentino (FI) in 1950

 Dipartimento di Chimica e Chimica Industriale, Via Risorgimento 35, I-56126 Pisa; E-mail:
 pampa@dcci.unipi.it.
 The research involves: i) the synthesis of derivatives of transition elements containing
 polyfunctional quinones; ii) the study of the activation of oxygen ligands by early transition
 metal halides; iii) metal complexes as precursors of functionalized inorganic matrices.
 i) Work has been done concerning complexes of 1,10-phenanthroline-5,6-dione of Groups 4, 5
 and 6 elements. We have found that 1,10-phenanthroline-5,6-dione is a useful starting material
 for the preparation of mono-, bi- and polynuclear compounds due to the presence of quinonoid
 and iminic functionalities on the same molecule. Work in this field will be continued aiming to
 the preparation of oligo- and heterometallic compounds containing polyfunctional quinones as
 bridging ligands, and to study their electronic and magnetic properties.
 ii) The coordination chemistry of the halides MX5 (M = Nb, Ta) with oxygen donor ligands has
 been scarcely developed heretofore. Recently, a variety of coordination compounds of this type
 has been prepared. The reactions must be carried out in strictly anhydrous conditions, and the
 products have been identified by means of IR and NMR spectroscopies, and X ray diffraction.
 The first step of these reactions is the simple coordination of the ligand to the metal. Hence, in
 some cases, some activation can take place. The target of this investigation is to extend the
 series of coordination compounds of MX5 with O-donor ligands, and to exploit the possibility to
 obtain functionalized organic molecules.
 iii) The implantation of metals on a solid matrix has attracted considerable interest in the last
 decades for the properties and implications in industrial processes of the resulting materials.
 Different methods can be used for the supportation on inorganic matrixes: the most common
 starts from metal hydrides or alkyls, or from low-valent transition metal derivatives such as
 metal carbonyls. In the framework of this research topic, we recently became interested in the
 implantation of Group 4 and 5 metals on silica surfaces in the form of metal N,N-
 dialkylcarbamates M(O2CNR2)n. The latter is a class of compounds recently used for the
 implantation of Sn(IV), late transition metals, and lanthanides on a surface of partially
 dehydroxylated silica.

 Keywords: Metal Complexes, quinones, metal halides, oxygenated ligands, implantation, silica,
 carbamates
SUPPLEMENTARY MATERIAL

Detailed list of the components of the research groups
 1. F. Marchetti, G. Pampaloni, S. Zacchini, Reactivity of Niobium(V) and Tantalum(V) Halides with Carbonyl Compounds:
    Synthesis of Simple Coordination Adducts, C–H bond Activation, C=O Protonation, and Halide Transfer, Dalton Trans., 2007,
    4343.
 2. L. Calucci, U. Englert, L. Margheriti, G. Pampaloni, C. Pinzino, A. Prescimone, 1,10-Phenanthroline-5,6-dione Complexes of
    Middle Transition Elements: Mono- and Dinuclear Derivatives, Inorg. Chim. Acta, 2008, 361, 2375.
 3. F. Marchetti, G. Pampaloni and S. Zacchini, From 1,2-Dialkoxyalkanes to 1,4-Dioxanes. A Transformation Mediated by NbCl5 via
    Multiple C–O Bond Cleavage at Room Temperature, Chem. Commun, 2008, 3651.
 4. F. Marchetti, G. Pampaloni, S. Zacchini, The Reactivity of 1,1-Dialkoxyalkanes with Niobium and Tantalum Pentahalides.
    Formation of Coordination Compounds, C–H and C–C Bonds Activation and the X-Ray Structure of the Stable Carboxonium
    Species [Me2C=CHC(=OMe)Me][NbCl5(OMe)], Dalton Trans., 2009, 8096.
 5. L. Calucci, C. Forte, G. Pampaloni, C. Pinzino, F. Renili, Chemical Implantation of Group 4 Cations on Silica via
    Cyclopentadienyl- and N,N-Dialkylcarbamato Derivatives, Inorg. Chim. Acta, 2010, 363, 33.
 6. R. Bini, C. Chiappe, F. Marchetti, S. Zacchini, G. Pampaloni, The Structures and the Unusual Rearrangements of Coordination
    Adducts of MX5 (M = Nb, Ta; X = F, Cl) with Simple Diethers. A Crystallographic, Spectroscopic and Computational Study,
    Inorg. Chem., 2010, 49, 339.
(permanent staff, included graduated students and postdocs)

Name                 Surname                  Position * Affiliation
Guido                Pampaloni                PA          Università di Pisa
Fabio **             Marchetti                RU          Università di Pisa
Fabio***             Marchetti                PA          Università di Pisa
Filippo              Renili                   PhD         Università di Pisa
*: PO = full professor; PA = associated professor; RU = university researcher; PhD = graduated
student; PoD = postdoctoral fellows; RC = CNR staff; T = technician
** Born in Bologna in 1974
*** Born in Castelfiorentino (FI) in 1950


Apparatus
(minimum value 25.000 € per item)

Type                                                 Producer                         Year of
                                                                                     acquisition
NMR Spectrometer Varian Gemini 200BB                 Varian                        1992
NMR Bruker Avance DRX 400 Spectrometer for           Bruker                        2009
high resolution and solid state spectra
Bruker AXS P4 Diffractometer                         Bruker                        1995
Bruker AXS D8 Powder Diffractometer                  Bruker                        2002
FTIR spectrometer Spectrum One with ATR              PerkinElmer                   2005
accessory
FTIR spectrometer Spectrum 100 with extended         PerkinElmer                   2009
range (7800-225 cm1)
Stirred high pressure reactor 300 mL with            Parr Instrument Company       2009
temperature control
Microscope SteREO Discovery.V8 supplied with         Zeiss                         2008
photo-camera


Technical skills

•   Synthesis and characterization of organometallic and coordination compounds.
•   Study of the reactivity of organometallic and coordination compounds.